For over a century scientists interested in the nervous system have postulated various mechanisms the brain uses to deal with the visual stimulation resulting from eye movements: "corollary discharge" (e.g., Helmholtz), proprioception (e.g., Sherrington) and complex visual stimulation (e.g., Gibson). We have found that the brain deals with one aspect of this problem, the elimination of visual stimulation generated by its own rapid eye movements using not one but several mechanisms. In the primary visual cortex, which we think is closely related to visual perception, we found that cells behave in ways we would expect if these cells underlie perception during eye movements. The primary mechanism here appears to be visual interaction. In the other branch of the visual system, we found that activity from oculomotor areas of the brain reduce the sensitivity of the superior colliculus cells to visual stimulation -- a potent corollary discharge. But rather than a perceptual function (which is usually postulated) we suggest that this corollary discharge eliminates spurious self-generated visual signals from reaching the oculomotor system and initiating a subsequent eye movement. BIBLIOGRAPHIC REFERENCES: Kunzle, H., Akert, K. and Wurtz, R.H.: Projection of area 8 (frontal eye field) to superior colliculus in the monkey. An autoradiographic study. Brain Res. 117: 487-492, 1976. Mohler, C.W. and Wurtz, R.H.: Role of striate cortex and superior colliculus in visual guidance of saccadic eye movements in monkeys. J. Neurophysiol 40: 74-94, 1977.